The avulsion

Ask the room

You are doing this case. Where is the danger, and what is your first move if it happens?

Take answers before advancing. The point of the debrief is what they say now, not what the next slide says.

• A basket engaged on a fragment too large to pass turns every pull on the scope into traction on the weakest segment of the ureter.

ureteroscope view

1. Cystoscopy, then a safety guidewire passed up the ureter into the renal pelvis under vision and fluoroscopy.
2. Semirigid ureteroscopy alongside the wire, inspecting the ureter up to the stone with gentle irrigation.
3. Laser fragmentation, dusting the stone or reducing it to fragments small enough to pass spontaneously.
4. For the upper ureter or kidney, a flexible scope over the wire, often through a ureteric access sheath placed under fluoroscopy.
5. Basket only small, free fragments under direct vision, never an impacted stone wider than the lumen.
6. Final inspection of the whole ureter for mucosal integrity.
7. JJ stent placed over the wire, with a check that both ends sit correctly.

• The ureter avulses when a basket grips a stone too wide for the lumen and the whole assembly is dragged down.
• The wall fails at its weakest point, the upper ureter.
• Three things stack.
• An impacted proximal stone, often softened or scarred by previous shockwave lithotripsy, sits in a basket closed firmly around it.
• The operator withdraws the engaged basket, or forces a scope or oversized access sheath through a tight upper segment.
• Because the proximal wall is thin and poorly supported, longitudinal traction concentrates there.
• A short pull strips the mucosa inside out.
• Sustained pull degloves a long segment, the scabbard avulsion, or breaks the ureter at two points and delivers a tube of ureter on the scope.
• The give is sudden and unmistakable.
• What comes back is not stone but ureter.

• Impacted stone in the proximal ureter
• Basketing a fragment wider than the lumen
• Previous shockwave lithotripsy or a strictured segment
• Pulling an engaged basket or scope against resistance
• Oversized access sheath forced through a narrow upper ureter

1. Stop pulling. Do not yank the basket or the scope. Resistance on withdrawal is a warning, not something to power through.
2. If a stone is basketed and stuck, disengage it: open the basket, laser the stone through the basket to release it, or cut the basket wire at the handle and leave it to retrieve later. Never force a stuck basket.
3. Inspect the ureter along its length under vision. Look for inverted mucosa, a circumferential defect, or a free tube of ureter on the instrument.
4. If avulsion is confirmed, treat it as a major ureteric injury: keep a wire to the kidney if one is still in place, stop, and call the senior on-call urologist. This is the conversion and escalation trigger. escalation trigger
5. Preserve the kidney and control urine drainage. A nephrostomy with a damage-control approach is reasonable when immediate reconstruction is not feasible.
6. Plan definitive repair by level and length: ureteroneocystostomy or Boari flap for distal loss, ileal ureter or autotransplantation for long proximal loss, usually open or staged.
7. Document fully: stone position, instrument and basket used, the moment and nature of the give, the segment lost, wire and drainage status, the senior informed, and the consent and counselling for reconstruction.

Three questions

1. Why is the proximal ureter the segment that avulses?
2. A basket is stuck on a stone in the upper ureter. What are your options?
3. You have a long proximal avulsion. How is it definitively managed?

Answers are on the card under the viva section. Hold them back until everyone has tried.

• Anyone can say repair the ureter.
• The strong answer leads with prevention, never basketing a stone wider than the lumen and lasering first, names disengaging a stuck basket by lasing through it or cutting the wire rather than pulling, and matches the reconstruction to the level and length of loss rather than offering one generic operation.